蓖麻对镉的耐性机制及有机酸对镉积累调控作用

发布时间：2018-05-16 10:56

本文选题：蓖麻 + 镉　；参考：《内蒙古农业大学》2016年博士论文

【摘要】：随着工农业生产排污量的增加,我国一些地区土壤Cd污染趋于加重的态势。蓖麻对Cd具有较高的耐性和富集能力,同时也是一种能源植物,利用蓖麻修复Cd污染土壤是一种合理有效的途径。本文研究了10、20、30、40和50mg/kg5个浓度Cd胁迫下蓖麻主栽品种对Cd的耐性和富集特征,筛选了不同Cd耐性和累积性蓖麻品种,从抗氧化酶活性、Cd亚细胞区隔化和亚细胞Cd形态3个方面研究了不同耐性和累积性蓖麻品种对Cd耐性和解毒机制以及不同种类有机酸对它们Cd累积的调控作用。研究结果如下：1.12个蓖麻品种对不同浓度Cd胁迫的生长响应与耐受程度存在显著差异,通过对相对株高、相对根长、相对叶绿素含量、相对地上部生物量和相对地下部生物量进行综合评价,并采用主成分分析、平均隶属函数分析和聚类分析,可将12种蓖麻品种划分为高耐性和低耐性两类,其中5个蓖麻品种是高耐性品种,7个蓖麻品种是低耐性品种。2.不同浓度Cd胁迫下蓖麻地上部Cd的含量大小顺序均为：茎部叶部。不同蓖麻品种地上部Cd累积量存在显著差异,根据蓖麻地上部Cd累积量差异大小可将蓖麻品种分为高累积性和低累积性两类,再结合蓖麻的耐性,可将12个蓖麻品种分为低耐低累积、低耐高累积、高耐低累积和高耐高累积4种类型。3.不同耐性累积性蓖麻品种对Cd的抗氧化防卫机制不同。Cd胁迫下高耐性品种通蓖5号和通蓖6号的抗氧化酶活性显著高于低耐性品种晋蓖2号和哲蓖2号;随Cd胁迫浓度的增加,高耐性品种SOD、POD和CAT活性基本保持不变或升高,胁迫产生的活性氧能被及时清除；低耐性品种在高浓度Cd胁迫下,SOD、POD和CAT活性受到抑制,累积的活性氧不能被及时清除。随着Cd胁迫浓度的增加,高累积品种叶SOD、POD和CAT活性变化幅度高于低积累性品种,根SOD和POD活性变化幅度低于低累积品种。同一蓖麻品种不同器官抗氧化防卫机制也不同,叶的抗氧化酶活性显著高于根；过氧化氢酶(CAT)可能在蓖麻根抗氧化胁迫中起主导作用,超氧化物歧化酶(SOD)和过氧化物酶(POD)可能在蓖麻叶抗氧化防卫中起主导作用。4.不同耐性累积性蓖麻品种对Cd的亚细胞区分布和亚细胞Cd化学形态也不同。Cd在蓖麻亚细胞含量大小顺序均为细胞可溶组分细胞壁细胞器；低耐性品种晋蓖Cd在蓖麻亚细胞含量大小顺序均为细胞可溶组分细胞壁细胞器；低耐性品种晋蓖2号和哲蓖2号细胞器中Cd的分配比例较高耐性品种通蓖5号和通蓖6号细胞器中Cd的分配比例高；高累积品种晋蓖2号和通蓖6号细胞可溶组分中Cd的分配比例较低累积品种哲蓖2号和通蓖5号细胞可溶组分中Cd的分配比例高。低耐性品种晋蓖2号和哲蓖2号叶主要以活性较高的乙醇提取态和去离子水提取态存在,而高耐性品种叶以活性较低的醋酸提取态存在；低累积品种根残渣态Cd含量较高,高累积品种根去离子水提取态Cd含量较高；去离子水提取态负责Cd从蓖麻根部向地上部的运输,残渣态限制了Cd从根部向地上部的运输。5.施用有机酸对Cd富集和转运能力的调控效果因有机酸种类、蓖麻品种及器官不同而异,有机酸对不同蓖麻品种Cd转运和富集能力提高效果的大小顺序为：通蓖6号晋蓖2号通蓖5号哲蓖2号；对蓖麻叶和茎中Cd转运和富集能力提高效果的大小顺序均为EDTACATA,对根的效果为EDTA≈TACA.6.施用有机酸对蓖麻生物量和总Cd累积量的调控效果因蓖麻品种、有机酸种类及浓度不同而异。EDTA加剧了Cd对蓖麻的毒害,但通蓖5号和通蓖6号表现出了较好的EDTA耐性；低浓度CA和TA能够缓解Cd对蓖麻的毒害、提高蓖麻的生物量,以通蓖5号和通蓖6号生物量提高的较多。lmmol/kg EDTA可显著提高晋蓖2号总Cd累积量,达到70.82μ g/株；1 mmol/kg CA可显著提高通蓖5号总Cd累积量,达到49.77μg/株；5 mmol/kg EDTA可显著提高通蓖6号总Cd累积量,达到102.88μg/株；有机酸对哲蓖2号总Cd累积量的影响微弱。
[Abstract]:With the increase of sewage discharge in industrial and agricultural production, soil Cd pollution in some areas of China tends to aggravate. Castor has high tolerance and enrichment ability to Cd, and it is also a kind of energy plant. It is a reasonable and effective way to repair Cd contaminated soil by castor bean. This paper studied castor under the stress of 10,20,30,40 and 50mg/kg5 under Cd stress. The resistance and accumulation of different Cd tolerance and accumulation of castor species were screened for the tolerance and accumulation of Cd by the main cultivars. The study on the tolerance and detoxification mechanism of different tolerance and cumulative castor varieties to Cd and the regulation of different kinds of organic acids on their Cd accumulation were studied in the 3 aspects of antioxidant enzyme activity, Cd subcellular septum and subcellular Cd morphology. The results are as follows: there are significant differences in the growth response and tolerance of 1.12 castor varieties to different concentrations of Cd stress. Through the comprehensive evaluation of relative plant height, relative root length, relative chlorophyll content, relative aboveground biomass and relative underground biomass, principal component analysis, average membership function analysis and cluster analysis are used. 12 varieties of castor species can be divided into two types of high tolerance and low tolerance, of which 5 castor varieties are high tolerance varieties, 7 castor varieties are low tolerance varieties.2. under different concentrations of Cd stress, the order of Cd in the upper castor ground is: stem leaves. The accumulation of Cd in the upper part of different castor species is significantly different, according to the upper castor ground The difference of Cd accumulation can be divided into two types of high accumulation and low accumulation of castor species, which can be combined with the tolerance of castor bean. 12 castor varieties can be divided into low tolerance, low accumulation, low and high accumulation, 4 types of high tolerance, low accumulation and high accumulation resistance, and 4 kinds of.3. tolerant accumulative castor species with high tolerance to the antioxidant defense mechanism of Cd under different.Cd stresses The antioxidant enzyme activity of tongcastor No. 5 and Tongan No. 6 was significantly higher than that of the low tolerance variety Jinyou 2 and zhe castor No. 2. With the increase of Cd stress, the activity of SOD, POD and CAT remained unchanged or increased, and the reactive oxygen species produced by stress were removed in time; the activity of SOD, POD and CAT under the high concentration of Cd stress was affected by the low tolerance Cd. The accumulated active oxygen can not be removed in time. With the increase of Cd stress concentration, the activity of SOD, POD and CAT in high accumulative leaves is higher than that of low accumulative varieties. The activity of SOD and POD in root is lower than that of low accumulative varieties. The antioxidant defense mechanism of different organs of the same castor species is different, and the antioxidant enzyme activity of the leaves is significant. Higher than root; catalase (CAT) may play a leading role in the antioxidant stress of castor root, superoxide dismutase (SOD) and peroxidase (POD) may play a leading role in the anti oxidative defense of castor leaf..4. different tolerance accumulative castor species distribution to the subcellular region of Cd and the chemical form of subcellular Cd, and.Cd in castor subthin. The order of cell content was cell wall cell organelles, and the low tolerance variety Shanxi Cd was cell wall organelles in the order of castor subcellular content, and the distribution of Cd in the low tolerance variety Jinyou 2 and zhe castor No. 2 was higher than that of Tongan 5 and tongcastor 6 cell organelle. The distribution ratio of Cd in the soluble components of high accumulative variety Jin castor No. 2 and tongcastor No. 6 was higher than that in the soluble components of zhe castor 2 and Tongan 5. The low tolerance variety Jinyou 2 and zhe castor 2 were mainly extracted from the extraction state of ethanol and deionized water, and the high tolerance was high. The leaves of the cultivar were in the presence of low activity of acetic acid; the content of Cd in the root residue of low accumulative varieties was higher, and the content of Cd in the deionized water of high accumulative varieties was higher. The extraction state of the deionized water was responsible for the transport of Cd from the root of castor to the ground, and the residue State restricted the enrichment of Cd by the application of organic acid to the transport.5. from the root to the ground. The control effect of transport capacity was different from the varieties of organic acids, castor varieties and organs. The order of the effect of organic acids on Cd transport and enrichment ability of different castor bean varieties was: Tongan No. 6, No. 2 tongcastor No. 5, No. 2 of zhe castor, tongcastor, and the order of Cd transport and enrichment in castor leaf and stem was EDTACATA, The effect of root effect was that the effect of organic acids on the biomass and total Cd accumulation of castor plant with EDTA TACA.6. increased the toxicity of Cd to castor plant by different kinds of organic acids and different concentrations of.EDTA, but Tongan 5 and Tongan 6 showed good EDTA tolerance. Low concentration of CA and TA could alleviate the toxicity of Cd to castor bean and increase castor The biomass of hemp, with the increasing.Lmmol/kg EDTA of Tongan 5 and Tongan No. 6, can significantly increase the total Cd accumulation of Shanxi castor No. 2 and reach 70.82 g/ strain; 1 mmol/kg CA can significantly increase the total Cd accumulation of Tongyou No. 5, and reach 49.77 mu g/ strain; 5 mmol/kg EDTA can significantly increase the total Cd accumulation of Tongan 6, up to 102.88 mu g/ plant; organic The effect of acid on the total Cd accumulation of zhe castor No. 2 was weak.

【学位授予单位】：内蒙古农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S565.6

【参考文献】